Oliver Kretschmar

Masked left ventricular restriction in elderly patients with atrial septal defects: A contraindication for closure?

The impact of an atrial septal defect in the elderly with reduced diastolic elasticity of the left ventricle is unclear. We studied the hemodynamic changes during balloon occlusion of atrial septal defects in patients over 60 years of age. In 18 patients (61–78 years old; median, 70), the left atrial pressure and the mitral valve inflow was measured during complete balloon occlusion of the defect and after deflation of the balloon. In seven patients, the left atrial pressure and the E/A ratio of the mitral valve inflow increased markedly (P = 0.02). Mean atrial pressures reached values of 27 mm Hg and the v‐wave peak values of 55 mm Hg. Two patients received a transcatheter device closure and developed congestive heart failure. In the elderly, an atrial septal defect can have a decompressive impact on the left ventricle. Therefore, caution appears to be warranted if atrial septal closure is planned. Cathet Cardiovasc Intervent 2001;52:177–180.

Acute haemodynamic changes after percutaneous mitral valve repair: relation to mid-term outcomes

Background Percutaneous mitral valve repair (MVR) using the Evalve MitraClip has been recently introduced as a potential alternative to surgical MVR. Objective To assess immediate haemodynamic changes after percutaneous MVR using right heart catheterisation. Design Single-centre longitudinal cohort study. Setting Tertiary referral centre. Patients Fifty consecutive non-surgical patients (age 74±14 years, EuroSCORE 26±14) with moderate to severe (3+) and severe (4+) mitral regurgitation (MR) due to functional (56%), degenerative (30%) or mixed (14%) disease were selected. Interventions MitraClip implantation was performed under general anaesthesia with fluoroscopy and echocardiographic guidance. Haemodynamic variables were obtained before and after MVR using standard right heart catheterisation and oximetry. Main outcome measures Haemodynamic changes immediately before and after MVR. Results Acute procedural success (reduction in MR to grade 2+ or less) was achieved in 46 (92%) patients. Mitral valve clipping reduced mean pulmonary capillary wedge pressure (mPCWP) (from 17±7 to 12±5 mm Hg), PCWP v-wave (from 24±11 to 16±7 mm Hg) and mean pulmonary artery pressure (mPAP) (from 29±12 to 24±6 mm Hg), and increased the cardiac index (CI) (from 3.1±1.0 to 3.9±1.1 l/min/m2) (all p<0.05). On Cox univariate regression analysis, mPCWP, PCWP v-wave- and mPAP-changes were associated with death, open-heart surgery for MR and/or hospitalisation for heart failure on follow-up. Conclusion In a heterogeneous population with predominantly functional MR, percutaneous MVR with the Evalve MitraClip system lowers mPCWP, PCWP v-wave and mPAP by 20%, 20% and 8%, respectively, and increases the CI by 32%.

Prenatally engineered autologous amniotic fluid stem cell-based heart valves in the fetal circulation

Prenatal heart valve interventions aiming at the early and systematic correction of congenital cardiac malformations represent a promising treatment option in maternal-fetal care. However, definite fetal valve replacements require growing implants adaptive to fetal and postnatal development. The presented study investigates the fetal implantation of prenatally engineered living autologous cell-based heart valves. Autologous amniotic fluid cells (AFCs) were isolated from pregnant sheep between 122 and 128 days of gestation via transuterine sonographic sampling. Stented trileaflet heart valves were fabricated from biodegradable PGA-P4HB composite matrices (n = 9) and seeded with AFCs in vitro. Within the same intervention, tissue engineered heart valves (TEHVs) and unseeded controls were implanted orthotopically into the pulmonary position using an in-utero closed-heart hybrid approach. The transapical valve deployments were successful in all animals with acute survival of 77.8% of fetuses. TEHV in-vivo functionality was assessed using echocardiography as well as angiography. Fetuses were harvested up to 1 week after implantation representing a birth-relevant gestational age. TEHVs showed in vivo functionality with intact valvular integrity and absence of thrombus formation. The presented approach may serve as an experimental basis for future human prenatal cardiac interventions using fully biodegradable autologous cell-based living materials.

Cardiac output measurement in children: comparison of Aesculon® cardiac output monitor and thermodilution

BACKGROUND We compared cardiac output (CO) measurements by the non-invasive electrical velocimetry (Aesculon) monitor with the pulmonary artery catheter (PAC) thermodilution method in children. METHODS CO values using the Aesculon monitor and PAC thermodilution were simultaneously recorded during cardiac catheterization in children. Measurements were performed under general anaesthesia. To compare, three consecutive measurements for each patient within 3 min were obtained. The means of the three values were compared using simple regression and Bland-Altman analysis. Data were presented as mean (sd). A mean percentage of <30% was defined to indicate clinical useful reliability of the Aesculon monitor. RESULTS A total of 50 patients with a median (range) age of 7.5 (0.5-16.5) yr were enrolled in the study. Mean CO values were 3.7 (1.5) litre min(-1) (PAC thermodilution) and 3.1 (1.7) litre min(-1) (Aesculon) monitor). Analysis for CO measurement showed a good correlation between the two methods (r=0.894; P<0.0001). The bias between the two methods was 0.66 litre min(-1) with a precision of 1.49 litre min(-1). The mean percentage error for CO measurements was 48.9% for the Aesculon monitor when compared with PAC thermodilution. CONCLUSIONS Electrical velocimetry using the Aesculon monitor did not provide reliable CO values when compared with PAC thermodilution. Whether the Aesculon monitor can be used as a CO trend monitor has to be assessed by further investigations in patients with changing haemodynamics.

Mortality and neurodevelopmental outcome at 1 year of age comparing hybrid and Norwood procedures

OBJECTIVES Neonates with hypoplastic left heart syndrome (HLHS) are at risk of high mortality and neurodevelopmental morbidity. As an alternative to Norwood-type stage I palliation, the hybrid procedure has been developed. It consists of bilateral pulmonary artery banding, catheter-based stenting of the arterial duct and balloon atrioseptostomy and delays open-heart surgery. Thus, it may be associated with a better outcome. The aim of this study was to determine the mortality and neurodevelopmental outcome in patients with HLHS and other univentricular heart (UVH) defects treated with hybrid or Norwood procedures. METHODS Thirty-one children (18 males) with HLHS and other UVH defects undergoing Norwood or hybrid procedure between 2004 and 2008 were consecutively enrolled. Mortality and neurodevelopmental outcome at 1 year of age were determined. RESULTS One-year mortality was 36% (31% in the hybrid vs. 39% in the Norwood group, P=0.71). Predictors of mortality were lower birth weight (P=0.02), older age at first procedure (P=0.02) and smaller size of ascending aorta (P=0.05). Overall, median psychomotor development index (PDI) and mental development index (MDI) of the Bayley Scales of Infant Development II were lower than the norm of 100 [PDI 57 (49-99), P<0.001; MDI 91 (65-109), P=0.002]. No effect of surgical treatment on neurodevelopmental outcome was found. Predictors of impaired motor outcome were length of hospital stay (LOHS) (P=0.01), lower body weight at second procedure (P=0.004) and female sex (P=0.01). Predictors of impaired cognitive outcome were longer mechanical ventilation time (P=0.03), intensive care unit stay (P=0.04) and LOHS (P<0.001), respectively. CONCLUSIONS Mortality at 1 year of age is comparable between patients undergoing hybrid and Norwood procedures. Early neurodevelopmental outcome is significantly impaired in patients with both HLHS and other UVH defects. Multicentre randomized studies are needed to determine the long-term neurodevelopmental outcome of children treated with the hybrid procedure.

Akute Linksherzinsuffizienz nach interventionellem Verschluss eines Vorhofseptumdefekts

Congestive left ventricular failure after surgical closure of an atrial septal defect (ASD) has been repeatedly reported, particularly in the elderly. We present a case of left ventricular failure after a successful transcatheter closure of an ASD, which to our knowledge has not been described before.    In a 78-year-old woman (50 kg, 160 cm) with well-preserved left ventricular function (ejection fraction 65%) and without coronary artery disease or arterial hypertension, an ASD (Qp/Qs 1.6:1) was closed with an Amplatzer Septal Occluder without a residual shunt. Two hours after the procedure, she developed pulmonary edema due to left ventricular failure (increase of end-diastolic diameter from 42 mm to 54 mm, ejection fraction 20%), had to be mechanically ventilated for 24 hours and needed catecholamines for 4 days. High doses of diuretics were supplied until the ejection fraction normalized (32%). The patient could not be discharged until two weeks after intervention. A reduced preload for decades may predispose acute left ventricular failure, particularly in the elderly with compromised ventricular compliance. Eine Linksherzinsuffizienz nach Operation eines Vorhofseptumdefekts (ASD) ist – vor allem beim älteren Patienten – wiederholt beschrieben worden. Wir berichten erstmals von einer Dekompensation des linken Ventrikels nach erfolgreichem interventionellem ASD-Verschluss.    Bei einer 78-jährigen Patientin (50 kg, 160 cm) mit guter systolische Funktion des linken Ventrikels (Auswurffraktion 65%), ohne arteriellen Hypertonus und ohne koronare Herzkrankheit wurde ein Vorhofseptumdefekt (Qp/Qs=1,6:1) mit einem Amplatzer Septal Occluder restshuntfrei verschlossen. Zwei Stunden später entwickelte sie ein Lungenödem bei deutlich reduzierter linksventrikulärer Funktion (Auswurffraktion 20%, Anstieg des enddiastolischen Durchmessers von 42 auf 54 mm). Sie wurde für 24 Stunden beatmungs- und für 4 Tage katecholaminpflichtig. Die Patientin rekompensierte allmählich unter hohen Gaben von Diuretika und konnte zwei Wochen nach Intervention in einem im Vergleich zur Aufnahme leicht gebesserten Zustand entlassen werden. Die Verkürzungsfraktion des linken Ventrikels hatte sich normalisiert (32%). Eine über Jahrzehnte reduzierte Vorlast scheint insbesondere beim älteren Menschen mit reduzierter Ventrikelcompliance für die akute Insuffizienz des linken Ventrikels zu prädisponieren.

Comparison of tracheal tube cuff diameters with internal transverse diameters of the trachea in children.

Background:  In this study, we evaluated the ratio of the cuff diameters of the Microcuff paediatric tracheal tube (Microcuff PET, Weinheim, Germany) to fluoroscopically measured internal transverse tracheal diameters in children from birth to adolescence.

Comparison of surgical and interventional therapy of native and recurrent aortic coarctation regarding different age groups during childhood

OBJECTIVE The aim of the study was to analyze immediate results, rate of complications and re-interventions during medium-term outcome in pediatric patients with native or recurrent aortic coarctation. We focused on an age-related therapeutic approach comparing surgical and trans-catheter treatment. METHODS This is a retrospective, single-centre, clinical observational trial including 91 consecutive patients (age: 1 day-18 years) treated for native coarctation in 67 and recurrent aortic coarctation in 24 patients. Surgical treatment was performed in 56, trans-catheter treatment with balloon dilatation in 17, and by stent implantation in 18 patients. According to the age groups, we treated 48 children in group A (<6 months of age), 16 in group B (6 months-6 years), and 27 in group C (>6 years). A total of 41 patients in group A were operated (85%), patients in group B received either surgical or trans-catheter treatment (50% vs 50%), and 16 patients in group C were treated by stent implantation (62%). RESULTS Immediate results were excellent with a significant release of pressure gradient in all three age groups (64.7% in group A, 69.1% in group B, and 63.3% in group C). Complication rate and re-intervention rate (surgical and interventional) both were [corrected] comparable between the three age groups (complications: group A 8.3%, group B 6.3%, and group C 3.7%, [corrected] re-interventions: group A 16.6%, group B 18.8%, and group C 14.8%). [corrected] Midterm outcome after a median follow-up period of 17.5 months was satisfactory with a re-intervention-free survival after 17.5 months of 83.4%, 81.2%, and 81.5% in group A, group B, and group C, respectively. CONCLUSIONS The current strategy of an age-related therapy for native and recurrent aortic coarctation in our institution is surgery in infants <6 months (group A), either surgery or balloon dilatation in younger patients <6 years (group B), while in older children >6 years of age (group C) the trans-catheter treatment with stent implantation is an excellent alternative to surgery. Balloon dilatations showed limited results with an overall re-intervention rate of 53% and, therefore, should mainly be performed as a rescue procedure or in recurrent aortic coarctation in neonates.

Novel growth stent for the permanent treatment of vessel stenosis in growing children: An experimental study

Stent implantation in stenotic vessels of infants and small children is problematic because there is no ideal stent model that is small enough to be easily introduced into the infant femoral vein or artery and, at the same time, large enough to be dilated during growth to adult vessel diameters. To overcome this problem, we designed a new stent, the growth stent. This growth stent is a balloon‐expandable metal stent. Two longitudinal halves are connected with bioabsorbable sutures so that a circular stent is created. It was postulated that after absorption of the sutures the stent would not impede growth. Twenty of these stents were implanted in the aorta, pulmonary arteries, and inferior vena cava of piglets (average weight 6.9 kg). After 18 weeks (14–23 weeks) and a mean weight gain of 59 kg, none of the stented vessels showed any significant stenosis or pressure gradient, documented by angiography and catheter pullback. During fluoroscopy, the two halves of the stent were clearly separated in all animals. The growth stent has the potential to be nonrestrictive during vessel growth, and thus is a promising new device for the permanent treatment of stenotic vessels in infancy and childhood. Catheter Cardiovasc Interv 2004;62:506–510.

Severe Congenital Heart Defects Are Associated with Global Reduction of Neonatal Brain Volumes

OBJECTIVES To determine neonatal global and regional brain volumes in infants with congenital heart disease (CHD) in comparison with healthy controls and to determine brain growth. STUDY DESIGN Prospective cohort study in infants undergoing open-heart surgery for complex CHD. Global and regional volumetric measurements on preoperative cerebral magnetic resonance imaging were manually segmented in children without overt brain lesions. RESULTS Preoperative brain volumetry of 19 patients demonstrates reduction in total and regional brain volumes, without any specific regional predilection compared with 19 healthy control infants (total brain volume reduction: 21%, regional brain volume reduction 8%-28%, all P < .001). CONCLUSIONS Infants with CHD undergoing bypass surgery have smaller brain volumes prior to surgery without a specific regional predilection. This suggests a fetal origin of reduced brain growth.